Mmw physical layer downlink channel scheduling and control signaling

ABSTRACT

A wireless transmit/receive unit (WTRU) (e.g., a millimeter WTRU (mWTRU)) may receive a first control channel using a first antenna pattern. The WTRU may receive a second control channel using a second antenna pattern. The WTRU may demodulate and decode the first control channel. The WTRU may demodulate and decode the second control channel. The WTRU may determine, using at least one of: the decoded first control channel or the second control channel, beam scheduling information associated with the WTRU and whether the WTRU is scheduled for an mmW segment. The WTRU may form a receive beam using the determined beam scheduling information. The WTRU receive the second control channel using the receive beam. The WTRU determine, by demodulating and decoding the second control channel, dynamic per-TTI scheduling information related to a data channel associated with the second control channel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/977,613 filed on Apr. 9, 2014, the contents of whichare hereby incorporated by reference herein.

BACKGROUND

For the last few decades the number of mobile devices has grownexponentially thereby resulting in increase in demand for data and datadelivery capacity of mobile wireless networks. In order to meet thisrapidly growing demand for mobile data, a large number of smaller cellsmay be deployed. However, the bandwidth provided by heterogeneousnetworks include macro and small cell networks may not be adequate.Therefore other mechanisms, for example, use of millimeter wave (mmW)frequencies may be utilized to provide significant capacity improvementrelated to user-specific data transmission. The narrow beam pattern ofmmW beams, however, may pose challenges for standalone mmW base stationsolutions, e.g., in delivering cell-specific and/or broadcastinformation.

SUMMARY

A wireless transmit/receive unit (WTRU), e.g., a millimeter wave WTRU(mWTRU) may receive a first control channel using a first antennapattern. The first control channel may be one of: a common physicaldownlink directional control channel (PDDCCH), a physical downlinkcontrol channel (PDCCH), an enhanced PDCCH (EPDCCH), or a millimeterwave physical downlink control channel (mmPDCCH). The first controlchannel may be configured per beam. The first control channel may beread by multiple WTRUs. The first control channel may be carried using abroad beam (e.g., a long term evolution (LTE) beam) or a millimeter(mmW) beam.

The WTRU may receive a second control channel (e.g., a dedicated PDDCCH)using a second antenna pattern. The WTRU may demodulate and decode thefirst control channel and the second control channel. The resourceallocation of the first control channel and/or the second controlchannel may be received from a network, e.g., via higher layerssignaling. The first control channel may be carried using a mmW beam oran LTE beam that may be wider than the mmW beam used to carry the secondcontrol channel.

The WTRU may determine, using at least one of: the decoded first controlchannel or the decoded second control channel, beam schedulinginformation associated with the WTRU and whether the WTRU is scheduledfor an mmW segment. The beam scheduling information may include transmitand receive beam scheduling information. The WTRU may form a receivebeam using the determined beam scheduling and receive the second controlchannel using the receive beam, when the WTRU is scheduled for the mmWsegment. The WTRU may determine, by demodulating and decoding the secondcontrol channel, dynamic per-transmission time interval (TTI) schedulinginformation related to a data channel (e.g., a physical downlinkdirectional data channel (PDDDCH)) associated with the second controlchannel. The WTRU may receive the data channel using the dynamic per-TTIscheduling information.

The WTRU may determine a validity period associated with per-TTIscheduling information and applying the per-TTI scheduling informationto one or more mmW TTIs. The per-TTI scheduling information is identicalfor a plurality of consecutive TTIs within a subframe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented.

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A.

FIG. 1C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 1A.

FIG. 1D is a system diagram of another example radio access network andanother example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 1E is a system diagram of another example radio access network andanother example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 2 illustrates an exemplary millimeter wave (mmW) downlink system.

FIG. 3 illustrates examples of frequency and spatial filtering.

FIG. 4 illustrates an exemplary mmW downlink frame structure.

FIG. 5 illustrates exemplary downlink logical, transport, and physicalchannels in an mmW system.

FIG. 6 illustrates an example of multiplexing of a dedicated physicaldownlink directional control channel (PDDCCH) and a physical downlinkdirectional data channel (PDDDCH).

FIG. 7 illustrates an example of digitized beamforming in an mmW WTRU(mWTRU).

FIG. 8 illustrates an example of a phased antenna array (PAA) connectedto two RF chains.

FIG. 9 illustrates an example of a PAA connected to its respective RFchain.

FIG. 10 illustrates an exemplary narrow beam pattern.

FIG. 11 illustrates an exemplary broad beam pattern.

FIG. 12 illustrates an exemplary multiple beam pattern.

FIG. 13 illustrates an example of dynamic predictive scheduling per beampair.

FIG. 14 illustrates an exemplary mmW system with a fixed narrow beampattern.

FIG. 15 illustrates an example of a common physical directional downlinkcontrol channel (PDDCCH) and a dedicated PDDCCH scheduling of a physicaldownlink directional data channel (PDDDCH).

FIG. 16 illustrates an example of dedicated PDDCCH-only scheduling ofPDDDCH.

FIG. 17 illustrates an example of physical downlink control channel(PDCCH) scheduling of PDDDCH.

FIG. 18 illustrates an example of PDCCH scheduling of PDDDCH overmultiple transmission time intervals (TTIs).

FIG. 19 illustrates an example of enhanced physical downlink controlchannel (EPDCCH) scheduling of PDDDCH.

FIG. 20 illustrates an example of dedicated mmW PDCCH (mmPDCCH)scheduling of PDDDCH.

FIG. 21 illustrates an example of multiplexed mmPDCCH scheduling ofPDDDCH.

FIG. 22 illustrates an example of PDCCH and PDDCCH scheduling of PDDDCH.

FIG. 23 illustrates an example of enhanced PDCCH (EPDCCH) and PDDCCHscheduling of PDDDCH.

FIG. 24 illustrates an example of long term evolution (LTE) mediumaccess control (MAC) control element (CE) and dedicated PDDCCHscheduling of PDDDCH.

FIG. 25 illustrates an example of dedicated mmPDCCH and dedicated PDCCHscheduling of PDDDCH.

FIG. 26 illustrates an example of multiplexed mmPDCCH and dedicatedPDCCH scheduling of PDDDCH.

FIG. 27 illustrates an exemplary mmW system with an mmW broad beampattern.

FIG. 28 illustrates an example of multiplexed broad-beam-common PDDCCHscheduling of PDDDCH.

DETAILED DESCRIPTION

A detailed description of illustrative embodiments will now be describedwith reference to the various Figures. Although this descriptionprovides a detailed example of possible implementations, it should benoted that the details are intended to be exemplary and in no way limitthe scope of the application.

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications system 100may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, and/or 102 d (whichgenerally or collectively may be referred to as WTRU 102), a radioaccess network (RAN) 103/104/105, a core network 106/107/109, a publicswitched telephone network (PSTN) 108, the Internet 110, and othernetworks 112, though it will be appreciated that the disclosedembodiments contemplate any number of WTRUs, base stations, networks,and/or network elements. Each of the WTRUs 102 a, 102 b, 102 c, 102 dmay be any type of device configured to operate and/or communicate in awireless environment. By way of example, the WTRUs 102 a, 102 b, 102 c,102 d may be configured to transmit and/or receive wireless signals andmay include user equipment (UE), a mobile station, a fixed or mobilesubscriber unit, a pager, a cellular telephone, a personal digitalassistant (PDA), a smartphone, a laptop, a netbook, a personal computer,a wireless sensor, consumer electronics, and the like.

The communications system 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106/107/109, theInternet 110, and/or the networks 112. By way of example, the basestations 114 a, 114 b may be a base transceiver station (BTS), a Node-B,an eNode B, a Home Node B, a Home eNode B, a site controller, an accesspoint (AP), a wireless router, and the like. While the base stations 114a, 114 b are each depicted as a single element, it will be appreciatedthat the base stations 114 a, 114 b may include any number ofinterconnected base stations and/or network elements.

The base station 114 a may be part of the RAN 103/104/105, which mayalso include other base stations and/or network elements (not shown),such as a base station controller (BSC), a radio network controller(RNC), relay nodes, etc. The base station 114 a and/or the base station114 b may be configured to transmit and/or receive wireless signalswithin a particular geographic region, which may be referred to as acell (not shown). The cell may further be divided into cell sectors. Forexample, the cell associated with the base station 114 a may be dividedinto three sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, e.g., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 115/116/117,which may be any suitable wireless communication link (e.g., radiofrequency (RF), microwave, infrared (IR), ultraviolet (UV), visiblelight, etc.). The air interface 115/116/117 may be established using anysuitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 103/104/105 and the WTRUs 102a, 102 b, 102 c may implement a radio technology such as UniversalMobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA),which may establish the air interface 115/116/117 using wideband CDMA(WCDMA). WCDMA may include communication protocols such as High-SpeedPacket Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may includeHigh-Speed Downlink Packet Access (HSDPA) and/or High-Speed UplinkPacket Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface115/116/117 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (e.g.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106/107/109.

The RAN 103/104/105 may be in communication with the core network106/107/109, which may be any type of network configured to providevoice, data, applications, and/or voice over internet protocol (VoIP)services to one or more of the WTRUs 102 a, 102 b, 102 c, 102 d. Forexample, the core network 106/107/109 may provide call control, billingservices, mobile location-based services, pre-paid calling, Internetconnectivity, video distribution, etc., and/or perform high-levelsecurity functions, such as user authentication. Although not shown inFIG. 1A, it will be appreciated that the RAN 103/104/105 and/or the corenetwork 106/107/109 may be in direct or indirect communication withother RANs that employ the same RAT as the RAN 103/104/105 or adifferent RAT. For example, in addition to being connected to the RAN103/104/105, which may be utilizing an E-UTRA radio technology, the corenetwork 106/107/109 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106/107/109 may also serve as a gateway for the WTRUs102 a, 102 b, 102 c, 102 d to access the PSTN 108, the Internet 110,and/or other networks 112. The PSTN 108 may include circuit-switchedtelephone networks that provide plain old telephone service (POTS). TheInternet 110 may include a global system of interconnected computernetworks and devices that use common communication protocols, such asthe transmission control protocol (TCP), user datagram protocol (UDP)and the internet protocol (IP) in the TCP/IP internet protocol suite.The networks 112 may include wired or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another core network connected to one or moreRANs, which may employ the same RAT as the RAN 103/104/105 or adifferent RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, e.g., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 130, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment. Also, embodiments contemplate that thebase stations 114 a and 114 b, and/or the nodes that base stations 114 aand 114 b may represent, such as but not limited to transceiver station(BTS), a Node-B, a site controller, an access point (AP), a home node-B,an evolved home node-B (eNodeB), a home evolved node-B (HeNB orHeNodeB), a home evolved node-B gateway, and proxy nodes, among others,may include some or all of the elements depicted in FIG. 1B anddescribed herein.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip. A processor, such as the processor 118, may include integratedmemory (e.g., WTRU 102 may include a chipset that includes a processorand associated memory). Memory may refer to memory that is integratedwith a processor (e.g., processor 118) or memory that is otherwiseassociated with a device (e.g., WTRU 102). The memory may benon-transitory. The memory may include (e.g., store) instructions thatmay be executed by the processor (e.g., software and/or firmwareinstructions). For example, the memory may include instructions thatwhen executed may cause the processor to implement one or more of theimplementations described herein.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 115/116/117. For example, in one embodiment,the transmit/receive element 122 may be an antenna configured totransmit and/or receive RF signals. In another embodiment, thetransmit/receive element 122 may be an emitter/detector configured totransmit and/or receive IR, UV, or visible light signals, for example.In yet another embodiment, the transmit/receive element 122 may beconfigured to transmit and receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 115/116/117.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130, the removable memory 132, and/ormemory integrated with the processor 118. The non-removable memory 130may include random-access memory (RAM), read-only memory (ROM), a harddisk, or any other type of memory storage device. The removable memory132 may include a subscriber identity module (SIM) card, a memory stick,a secure digital (SD) memory card, and the like. In other embodiments,the processor 118 may access information from, and store data in, memorythat is not physically located on the WTRU 102, such as on a server or ahome computer (not shown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 115/116/117from a base station (e.g., base stations 114 a, 114 b) and/or determineits location based on the timing of the signals being received from twoor more nearby base stations. It will be appreciated that the WTRU 102may acquire location information by way of any suitablelocation-determination implementation while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is a system diagram of the RAN 103 and the core network 106according to an embodiment. As noted above, the RAN 103 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102 cover the air interface 115. The RAN 103 may also be in communicationwith the core network 106. As shown in FIG. 1C, the RAN 103 may includeNode-Bs 140 a, 140 b, 140 c, which may each include one or moretransceivers for communicating with the WTRUs 102 a, 102 b, 102 c overthe air interface 115. The Node-Bs 140 a, 140 b, 140 c may each beassociated with a particular cell (not shown) within the RAN 103. TheRAN 103 may also include RNCs 142 a, 142 b. It will be appreciated thatthe RAN 103 may include any number of Node-Bs and RNCs while remainingconsistent with an embodiment.

As shown in FIG. 1C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC 142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macrodiversity, security functions, data encryption, and thelike.

The core network 106 shown in FIG. 1C may include a media gateway (MGW)144, a mobile switching center (MSC) 146, a serving GPRS support node(SGSN) 148, and/or a gateway GPRS support node (GGSN) 150. While each ofthe foregoing elements are depicted as part of the core network 106, itwill be appreciated that any one of these elements may be owned and/oroperated by an entity other than the core network operator.

The RNC 142 a in the RAN 103 may be connected to the MSC 146 in the corenetwork 106 via an IuCS interface. The MSC 146 may be connected to theMGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices.

The RNC 142 a in the RAN 103 may also be connected to the SGSN 148 inthe core network 106 via an IuPS interface. The SGSN 148 may beconnected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between and the WTRUs102 a, 102 b, 102 c and IP-enabled devices.

As noted above, the core network 106 may also be connected to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 1D is a system diagram of the RAN 104 and the core network 107according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the core network 107.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode-Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1D, theeNode-Bs 160 a, 160 b, 160 c may communicate with one another over an X2interface.

The core network 107 shown in FIG. 1D may include a mobility managementgateway (MME) 162, a serving gateway 164, and a packet data network(PDN) gateway 166. While each of the foregoing elements are depicted aspart of the core network 107, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 162 may be connected to each of the eNode-Bs 160 a, 160 b, 160 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 162 may also provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 164 may be connected to each of the eNode-Bs 160 a,160 b, 160 c in the RAN 104 via the S1 interface. The serving gateway164 may generally route and forward user data packets to/from the WTRUs102 a, 102 b, 102 c. The serving gateway 164 may also perform otherfunctions, such as anchoring user planes during inter-eNode B handovers,triggering paging when downlink data is available for the WTRUs 102 a,102 b, 102 c, managing and storing contexts of the WTRUs 102 a, 102 b,102 c, and the like.

The serving gateway 164 may also be connected to the PDN gateway 166,which may provide the WTRUs 102 a, 102 b, 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and IP-enableddevices.

The core network 107 may facilitate communications with other networks.For example, the core network 107 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 107 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 107 and the PSTN 108. In addition, the corenetwork 107 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 1E is a system diagram of the RAN 105 and the core network 109according to an embodiment. The RAN 105 may be an access service network(ASN) that employs IEEE 802.16 radio technology to communicate with theWTRUs 102 a, 102 b, 102 c over the air interface 117. As will be furtherdiscussed below, the communication links between the differentfunctional entities of the WTRUs 102 a, 102 b, 102 c, the RAN 105, andthe core network 109 may be defined as reference points.

As shown in FIG. 1E, the RAN 105 may include base stations 180 a, 180 b,180 c, and an ASN gateway 182, though it will be appreciated that theRAN 105 may include any number of base stations and ASN gateways whileremaining consistent with an embodiment. The base stations 180 a, 180 b,180 c may each be associated with a particular cell (not shown) in theRAN 105 and may each include one or more transceivers for communicatingwith the WTRUs 102 a, 102 b, 102 c over the air interface 117. In oneembodiment, the base stations 180 a, 180 b, 180 c may implement MIMOtechnology. Thus, the base station 180 a, for example, may use multipleantennas to transmit wireless signals to, and receive wireless signalsfrom, the WTRU 102 a. The base stations 180 a, 180 b, 180 c may alsoprovide mobility management functions, such as handoff triggering,tunnel establishment, radio resource management, traffic classification,quality of service (QoS) policy enforcement, and the like. The ASNgateway 182 may serve as a traffic aggregation point and may beresponsible for paging, caching of subscriber profiles, routing to thecore network 109, and the like.

The air interface 117 between the WTRUs 102 a, 102 b, 102 c and the RAN105 may be defined as an R1 reference point that implements the IEEE802.16 specification. In addition, each of the WTRUs 102 a, 102 b, 102 cmay establish a logical interface (not shown) with the core network 109.The logical interface between the WTRUs 102 a, 102 b, 102 c and the corenetwork 109 may be defined as an R2 reference point, which may be usedfor authentication, authorization, IP host configuration management,and/or mobility management.

The communication link between each of the base stations 180 a, 180 b,180 c may be defined as an R8 reference point that includes protocolsfor facilitating WTRU handovers and the transfer of data between basestations. The communication link between the base stations 180 a, 180 b,180 c and the ASN gateway 182 may be defined as an R6 reference point.The R6 reference point may include protocols for facilitating mobilitymanagement based on mobility events associated with each of the WTRUs102 a, 102 b, 102 c.

As shown in FIG. 1E, the RAN 105 may be connected to the core network109. The communication link between the RAN 105 and the core network 109may defined as an R3 reference point that includes protocols forfacilitating data transfer and mobility management capabilities, forexample. The core network 109 may include a mobile IP home agent(MIP-HA) 184, an authentication, authorization, accounting (AAA) server186, and a gateway 188. While each of the foregoing elements aredepicted as part of the core network 109, it will be appreciated thatany one of these elements may be owned and/or operated by an entityother than the core network operator.

The MIP-HA may be responsible for IP address management, and may enablethe WTRUs 102 a, 102 b, 102 c to roam between different ASNs and/ordifferent core networks. The MIP-HA 184 may provide the WTRUs 102 a, 102b, 102 c with access to packet-switched networks, such as the Internet110, to facilitate communications between the WTRUs 102 a, 102 b, 102 cand IP-enabled devices. The AAA server 186 may be responsible for userauthentication and for supporting user services. The gateway 188 mayfacilitate interworking with other networks. For example, the gateway188 may provide the WTRUs 102 a, 102 b, 102 c with access tocircuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. In addition, the gateway 188 mayprovide the WTRUs 102 a, 102 b, 102 c with access to the networks 112,which may include other wired or wireless networks that are owned and/oroperated by other service providers.

Although not shown in FIG. 1E, it will be appreciated that the RAN 105may be connected to other ASNs and the core network 109 may be connectedto other core networks. The communication link between the RAN 105 theother ASNs may be defined as an R4 reference point, which may includeprotocols for coordinating the mobility of the WTRUs 102 a, 102 b, 102 cbetween the RAN 105 and the other ASNs. The communication link betweenthe core network 109 and the other core networks may be defined as an R5reference, which may include protocols for facilitating interworkingbetween home core networks and visited core networks.

Millimeter wave (mmW) systems may provide a large bandwidth that mayprovide capacity improvement for user-specific data transmission. Thenarrow beam patterns used in mmW systems may pose challenges for astandalone mmW-only eNodeB (eNB) solution, e.g., in deliveringcell-specific or broadcast information. A beam pattern may be referredto as an antenna pattern, an antenna beam pattern, a beam direction, ora channel. The beam pattern may be associated with a reference signal(e.g., unique reference signal) or an antenna port. mmW system designmay incorporate an add-on downlink mmW data transmission system into asmall cell LTE network.

A standalone mmW eNB may be provided. A small cell mmW eNB (SCmB)deployment may be based on a small cell deployment (e.g., a ThirdGeneration Partnership Project (3GPP), Release 12 (R12) based small celldeployment). mmW operation in such a deployment may be performed, forexample, by two network nodes. A small cell mmW eNB (SCmB) may be anlong term evolution (LTE) small cell eNB that may be capable ofoperating an mmW air interface. In parallel, the LTE small cell eNB mayoperate with an LTE air interface in the downlink. An SCmB may providean antenna configuration and beamforming technique that may allow theSCmB to transmit LTE channels in a wide beam pattern and mmW channels ina narrow beam pattern. The SCmB may transmit the wide beam pattern andthe narrow beam pattern. The wide beam pattern and the narrow beampattern may be transmitted simultaneously. To support WTRUs without mmWtransmitters, the SCmB may support a mode in which the uplink mayoperate the LTE air interface, e.g., only the LTE air interface. WTRU,e.g., an mmW WTRU (mWTRU), may be capable of operating an mmW downlinkair interface in parallel with the LTE air interface in the downlink.The mWTRU may have multiple sets of antennas (e.g., two sets ofantennas), and associated radio frequency (RF) chains (e.g., oneoperating in an LTE band and another operating in an mmW band). Eachinstance of antenna and an RF chain may be associated with a basebandprocessing function (e.g., an independent baseband processing function).The plurality of baseband functions may share one or more blocks, forexample, if the mmW air interface is similar to the LTE system. The mmWhardware and/or software may be implemented as a receiver.

One or more mmW channels (e.g., add-on mmW channels) may be implementedas part of a carrier aggregation scheme. In such a carrier aggregationscheme, a carrier type may be in an mmW frequency band but may apply adifferent air interface. mmW channels may be applied for high throughputor low latency traffic data applications. Control signaling, which mayinclude system information update, paging, radio resource control (RRC)and non-access stratum (NAS) signaling (e.g., signaling radio bearers),and/or multicast traffic, may be carried in LTE channels. Certain mmWcontrol signaling may use LTE channels.

FIG. 2 illustrates an exemplary mmW downlink data system 200. Asillustrated in FIG. 2 , due to potentially significant propagation loss,for example, in non-line-of-sight (NLOS) at the mmW frequency band, SCmBand/or mWTRU may employ narrow beamforming in transmit (Tx) and/orreceive (Rx) directions to ensure a satisfactory link budget for highthroughput and low latency traffic data. An example outage studyconducted at 28 GHz and 38 GHz in an urban area using a steerable 10°beam 24.5 dBi horn antenna at both the transmitter and the receiver mayindicate that a consistent coverage may be achieved with a cell radiusof 200 meters when such antennas are used.

The SCmB and mWTRU may employ a wider beam pattern for LTE operation,which may include cell search, random access, cell selection and/orreselection, etc. An omni-directional radiation pattern with an antennagain of 0 dBi may be used in simulation and development of LTEtechnologies, including beamforming.

The mmW downlink data system 200 may identify and mitigate the impact ofthe directivity in mmW transmit and/or receive beam patterns on a set ofprocedures that may include mmW physical layer control signaling,physical layer data scheduling, beam or channel measurement andfeedback, transmit and/or receive beam alignment, etc. Receivebeamforming may perform a narrow spatial filtering, as illustrated inFIG. 3 so that a mWTRU may see a channel impulse response in a specificspatial direction. A LTE WTRU may have an omni-directional receive beampattern and may perceive a superimposed channel impulse response overthe angular domain, e.g., the entire angular domain.

FIG. 3 illustrates a comparison between a frequency domain filtering andspatial/angular domain filtering. An aligned transmit/receive beam mayprovide an extra degree of freedom in the angular domain and may affordthe mmW layer a greater degree of spatial separation relative to an LTEsystem. This may be a result of the propagation of mmW and the largenumber of antenna elements that may be included in an mmW antenna. Forexample, the spatial filtering may result in an effective channel thatmay be fairly flat by excluding paths outside of its beam width.

The mmW system may use a carrier frequency of 28 GHz, 38 GHz, 60 GHz,etc. The system bandwidth may be variable, e.g., up to 1 GHz. Theestimated RMS delay spread may be approximately 100-200 ns with a narrowbeam pattern. Latency may be 1 ms. The waveform may be orthogonalfrequency division multiplexing (OFDM)-based or broadband single-carrierbased. Connectivity may be provided via an LTE small cell eNB with mmWadd-on channels and a plurality of RF chains, each connected to adifferent antenna. The data rate may be, e.g., 30 Mbit/s or more in thedownlink for 95% or more of WTRUs. Mobility may be achieved by providingan optimized data connection that may be sustained, for example, at aspeed of 3 km/h, and/or a data connection that may be maintained, forexample, at a speed of 30 km/h. Data rate and mobility criteria may bemet with a cell radius of, for example, less than 100 meters.

The candidates for the mmW air interface may include one or more ofbroadband cyclic prefixed single carrier (CP-SC), orthogonal frequencydivision multiplexing (OFDM), single carrier (SC)-OFDM, or multiplecarrier-code division multiple access (MC-CDMA). The aspects of one ormore of peak-to-average power ratio (PAPR) performance, sensitivity totransmitter non-linearity, bit error rate (BER) performance withdifferent equalization schemes ((zero-forcing decision feedbackequalization (ZF-DFE) or frequency-domain linear equalization (FD-LE)),resource channelization, multiple access scheme, or implementationcomplexity of each candidate may be taken into account, e.g., with thehelp of a simulation based on mmW channel modeling

A single carrier waveform may have good PAPR properties compared toOFDM, but may lack the ability to schedule resources dynamically in thefrequency domain and may be more difficult to channelize. The narrowbeams of the mmW antennas may limit the ability to perform frequencydomain scheduling. A simulation with accurate mmW channel modeling maybe used for a proper evaluation.

The OFDM waveform may be utilized. The SCmB may operate LTE and mmW airinterfaces, and a similar waveform may facilitate functional blocksharing between these two implementations, e.g., clock distribution andfast fourier transform (FFT) block. One or more implementationsdisclosed herein may be disclosed in the context of an OFDM-based mmWwaveform. However, certain system procedures may apply to a singlecarrier waveform, e.g., with minor modifications.

An OFDM frame structure may be provided. For example, to promoteflexibility in coordination between the LTE and mmW channels andpossibly enable common functional block sharing in an mWTRU device, themmW sampling frequency may be an integer multiple of the LTE minimumsampling frequency of 1.92 MHz. An mmW OFDM system may adopt asubcarrier spacing Δf that may be an integer multiple of the LTEsubcarrier spacing of 15 kHz, e.g., Δf=15*K kHz. The selection of theinteger multiple K and the resulting Δf may achieve a balance betweenthe sensitivity to the Doppler shift and different types of frequencyerrors and the ability to remove channel time dispersion. Orthogonalitybetween subcarriers may deteriorate and inter-subcarrier interferencemay increase when the Doppler shift increases in proportion to thesubcarrier spacing.

As the mmW downlink data link targets up to 30 km/h, the maximum Dopplershift at 28 GHz may be 778 Hz. The channel time dispersion on mmWfrequencies may be measured, and an example 28 GHz measurement in adense urban area indicates that an example root mean square (RMS) delayspread σ may be between 100 and 200 ns. The 90% coherence bandwidth maybe estimated at 1/50σ 100 kHz and the 50% coherence bandwidth at ⅕σ 1MHz. A subcarrier spacing between 100 kHz and 1 MHz may be reasonable.An example Δf may be 300 kHz, e.g., K=20. The wide subcarrier spacingmay be robust against Doppler shift and other types of frequency error,which may reduce the implementation difficulty.

The symbol length T_(symbol) of the OFDM system may be 1/Δf. If thesubcarrier spacing Δf is 300 kHz, the symbol length T_(symbol) may be3.33 μs. The cyclic parameter (CP) length may cover the entire length ofthe channel time dispersion to eliminate inter-symbol interference, butthe CP may carry the cost of additional power and reduced data rate,e.g., a system overhead. In an example in which T_(symbol) is 3.33 μs,the CP length T_(CP) may be selected as 1/14 of T_(symbol), e.g., 0.24μs, and the corresponding CP overhead may be 7% as calculated byT_(CP)/(T_(CP)+T_(symbol)).

To achieve low latency, the transmission time interval (TTI) length ofthe mmW downlink data enhancement may be reduced significantly comparedto the 1 ms TTI length of the LTE system. The mmW downlink may have asubframe length of 1 ms to line up with the LTE 1 ms subframe timing.The mmW subframe may include multiple TTIs, and the TTI length may beclosely tied to other frame structure parameters, such as subcarrierspacing, symbol length, CP length, FFT size, etc. Table 1 illustrates anexample list of OFDM parameters with a conservative CP, e.g., 4× channeldelay spread. CP length selection may be based on an assumption that thedelay spread over mmW frequencies may be lower than 200 ns.

TABLE 1 OFDM Numerology Parameters System bandwidth (MHz)  125  250  500 1000 Sampling rate (MHz)  153.6  307.2  614.4  1228.8 Sub-carrierspacing (kHz)  300  300  300  300 Number of sub-carrier per RB  12   12  12   12 RB bandwidth (MHz)   3.6   3.6   3.6   3.6 Number ofassignable RBs  32   64  128  256 Number of occupied sub-carriers  384 768  1536  3072 Occupied bandwidth (MHz)  115.2  230.4  460.8  921.6IDFT(Tx)/DFT(Rx) size  512  1024  2048  4096 OFDM symbol duration (us)  3.333   3.333   3.333   3.333 CP length (ratio to symbol length) 1/41/4 1/4 1/4 CP length (us)   0.833   0.833   0.833   0.833 Number ofsymbols per slot  24   24   24   24 Slot duration (us)  100  100  100 100 Sub-frame duration (ms)   1   1   1   1 Number of slots persub-frame  10   10   10   10 Frame duration (ms)  10   10   10   10Number of sub-frames per frame  10   10   10 Number of symbols per TTIper RB  288  288  288  288 Number of symbols per TTI using all RBs 921618432 36864 73728 Signaling overhead  20%   20%   20%   20% Data rateusing uncoded 64 QAM (Mbps)  442.368  884.736  1769.472  3538.944Spectral efficiency   3.538944   3.538944   3.538944   3.538944

FIG. 4 illustrates an exemplary frame structure 400 corresponding to theexample disclosed in Table 1. A longer CP may be considered for anextended cell radius as the extended CP is designed for in the LTEsystem. A longer CP may be considered for a more conservative approachto ensure the channel time dispersion is entirely covered in the CPlength. The nominal spectral efficiency may decrease as the overheadcaused by the CP length increases.

Certain example frame structures are disclosed in the context of anOFDM-based mmW downlink data enhancement that may be incorporated intoan OFDM-based LTE small cell network. Other waveform implementations,including, for example, broadband SC and MC-CDMA may use differentstructures and/or parameters. The general principles disclosed hereinmay be applicable to other waveform implementations that may be used formmW transmission.

The mmW downlink data enhancement may employ physical layer channels andreference signals as disclosed herein in addition to LTE physicalchannels. The mmW downlink data enhancement may employ a beam-specificreference signal (BSRS). BSRS may be a sequence associated with atransmit beam used for beam acquisition, timing and/or frequencysynchronization, channel estimation for a physical downlink directionalcontrol channel (PDDCCH), fine beam tracking, beam measurement, etc.BSRS may carry (e.g., implicitly carry) beam identity information. Theremay be different types of BSRS. For example, there may be BSRS for anmmW sector and its member segments. The segment may be used in a switchbeam system as disclosed herein and as illustrated, for example, in FIG.14 . The segment may be referred as a beam direction (e.g., a narrowbeam direction a wide beam direction).

A physical downlink directional data channel (PDDDCH) may be provided.PDDDCH may carry payload information received as a medium access controlprotocol data unit (MAC PDU) from the MAC layer. The resource allocationof this channel may be determined by the downlink scheduling informationcarried in PDDCCH. The PDDDCH for an mWTRU may be transmitted in anarrow transmit beam. The PDDDCH may be received in a paired narrowreceive beam. PDDDCHs for different WTRUs in different transmit/receivebeam pairs may apply at least one of identical time, frequency, or coderesources. Multiple PDDDCHs may operate in a transmit/receive beam pairusing multiple access in at least one of time, frequency, or codedomains.

A physical downlink directional control channel (PDDCCH) may beprovided. The PDDCCH may carry control information associated with datafor an mWTRU. The control information may be used to demodulate and/ordecode a PDDDCH associated with the PDDCCH. The PDDCCH may operate usinga transmit/receive narrow beam pair. The PDDCCH may apply similarmultiple user access. The PDDCCH may include a common PDDCCH and/or adedicated PDDCCH. The dedicated PDDCCH may be associated with a PDDCCHon a per-TTI basis. A common PDDCCH may include beam-specificinformation, such as segment identity, for an mWTRU to identify thetransmit beam. An mWTRU may read the common PDDCCH to find out whetherthe mWTRU is scheduled and the identification of the mmW beam pair to beused. The common and dedicated PDDCCHs may be placed separately in thetime and frequency domains. The common PDDCCH may be carried in a narrowor broad mmW beam. The dedicated PDDCCH may be located in a narrow mmWbeam.

A demodulation reference signal (DMRS) may be provided. The DMRS mayinclude signals embedded in the transmission for channel estimation forPDDDCH. The signals may be placed in time and frequency domains, forexample, according to a predefined pattern to ensure correctinterpolation and reconstruction of the channel.

One or more channels and reference signals may be beamformed identicallyand may be transmitted via a physical antenna port. The channels may usean mmW frequency band and may be applied for high speed, low latencyuser traffic applications. FIG. 5 illustrates an example downlinklogical, transport, and physical channels in an mmW system 500. Thesystem 500 may adopt a channel mapping with mmW related channels, e.g.,channels 502, 504, 506.

An mWTRU may have an associated PDDCCH when its data is transmitted inthe PDDDCH, e.g., utilizing the mWTRU's transmit/receive beam pair. Oneor more of Time Division Multiplexing (TDM), Frequency DivisionMultiplexing (FDM), or Hybrid Multiplexing may be applied. PDDCCH andPDDDCH may be multiplexed in the time domain in a TTI. The PDDCCH may bedecoded, and the PDDDCH demodulation and decoding may start before theend of a TTI. This may be less demanding of data buffering resources andmay reduce latency. PDDCCH occupancy of the allocated frequency spectrummay reduce the efficiency. PDDCCH and PDDDCH may be multiplexed in thefrequency domain in a TTI. PDDCCH and PDDDCH decoding may not startuntil the end of a TTI. An mWTRU may use a large buffer for the databecause the allocated bandwidth may be large in the mmW frequency band.This may increase the latency. Spectrum efficiency may be improved.PDDCCH and PDDDCH may be multiplexed in both time and frequency domainsto balance between TDM and FDM. FIG. 6 illustrates multiplexing ofdedicated Physical Downlink Directional Control Channel (PDDCCH) andPhysical Downlink Directional Data Channel (PDDDCH)

The mmW downlink data enhancement may be unidirectional, e.g., in thedownlink direction. mmW control information in the uplink may be carriedin LTE uplink control or data channels. Duplex schemes, such asfrequency division duplex (FDD), time division duplex (TDD), and/orspatial division duplex (SDD) may be utilized.

Multiple access may depend on the beamforming technique and may varywithin a beam (e.g., intra-beam) or between beams (e.g., inter-beam).Advanced baseband transmit beamforming may be used at the SCmB. Analogreceive beamforming may be used at the mWTRU.

Intra-beam multiple access may involve scheduling multiple mWTRUs in adownlink transmit beam. For example, frequency division multiple access(FDMA) may involve multiple mWTRUs assigned with different frequencyallocation and receiving simultaneously. The mWTRUs may receive a strongdownlink signal in similar angular incoming directions. The best beamfor one mWTRU may not be the best beam for another mWTRU. A jointlyconfigured (e.g., optimized) beam (e.g., suboptimal for all) may beused. The SCmB may schedule an mWTRU within a beam.

Time division multiple access (TDMA) may involve multiple mWTRUsassigned with frequencies allocated in the transmit beam. For example,in a slot, there may be one mWTRU receiving. In such a case, asuboptimal beam may not be used. However, the packet size may becomparatively large that may lead to packing inefficiencies.

Non-orthogonal multiple access (NOMA) may involve multiple mWTRUslocated at a distance from each other in the transmit beam and a largepath loss difference. The mWTRUs may use the same frequency and timeresources, e.g., non-orthogonal, but may use superposition coding andsuccessive interference cancellation (SIC) to remove the interferingsignal successively. The channel estimation for an mWTRU may use a morecomplex design.

Inter-beam multiple access may involve scheduling multiple mWTRUs indifferent downlink transmit beams. Spatial division multiple access(SDMA) may involve multiple mWTRUs assigned in different transmit beams.The mWTRUs may be allocated with identical frequency resources and mayreceive simultaneously (e.g., MU-MIMO). Receive beamforming may useinterference rejection combining (IRC). FDMA may involve multiple mWTRUsassigned in different transmit beams allocated with different frequencyresources. TDMA may involve multiple mWTRUs assigned in differenttransmit beams assigned with identical frequency resources and receivingin turn according to scheduling. This may be similar to intra-beam TDMA.

An mWTRU may use a phase antenna array to achieve an antenna gain forcompensating for the high path loss at mmW frequencies, at which theshort wavelength may allow a compact form factor of the device design.While an element spacing of 0.5λ may be used in theoretical performanceanalysis, in practice a larger spacing, such as 0.7λ, may be applied.

An antenna element may have a dedicated RF chain, which may include RFprocessing and analog-to-digital conversion (ADC) as illustrated in FIG.7 . The signal processed by an antenna element may be controlledindependently in phase and/or amplitude to configure (e.g., optimize)the channel capacity. While this mWTRU antenna configuration may providevery high performance, it may have a high cost and complexity inimplementation and high energy consumption in operation.

An mWTRU may employ a hybrid approach in which analog beamforming may beperformed over phase array elements associated with a phase shifter andconnected to an RF chain. The phase of the signal at an antenna elementmay be adjusted in the beamforming. Digital precoding may be applied onthe baseband signals of one or more RF chains (e.g., all RF chains) whenthere is more than one RF chain. Spatial diversity and MIMO schemes maybe implemented using digital precoding.

System parameters of hybrid beamforming may include a number of datastreams N_(DATA), a number of RF chains (TRX) N_(TRX), a number ofantenna ports N_(AP), a number of antenna elements N_(AE), and/or anumber of phase antenna arrays N_(PAA).

In an example, N_(PAA) may be less than or equal to N_(AP) that may beless than or equal to N_(TRX) that in turn may be less than or equal toN_(AE). A PAA may include multiple antenna elements. For example, a 4×4PAA may have 16 antenna elements. An antenna port may be defined suchthat the channel over which a symbol on the antenna port is conveyed maybe inferred from the channel over which another symbol on the sameantenna port is conveyed. One resource grid per antenna port may beprovided. Cell-specific reference signals may support a configuration ofone, two, or four antenna ports and may be transmitted on antenna portsp=0, p∈{0,1} and p∈{0,1,2,3}, respectively. Multicast-broadcastsingle-frequency network (MBSFN) reference signals may be transmitted onantenna port p=4. mWTRU-specific reference signals associated withphysical downlink shared channel (PDSCH) may be transmitted on one ormore antenna ports p=5, p=7, p=8, or one or more ofp∈{7,8,9,10,11,12,13,14}. Demodulation reference signals associated withenhanced physical downlink control channel (EPDCCH) may be transmittedon one or more of antenna ports p∈{107,108,109,110}. Positioningreference signals may be transmitted on antenna port p=6. CSI referencesignals may support a configuration of one, two, four, or eight antennaports and may be transmitted on antenna ports p=15, p∈{15,16},p∈{15,16,17,18}, and p∈{15,16,17,18,19,20,21,22}, respectively. Anantenna port may carry a beamformed reference signal associated with theantenna port that may be used to identify the antenna port.

A phase antenna array (PAA) may be connected to one or more RF chains,depending on the system requirement and/or configuration. FIG. 8illustrates a PAA 802 that may be connected to RF chains 804, 806. ThePAA 802 may be of a size 4×4. The RF chains 804, 806 may have sets of 16phase shifters. The PAA 802 may form two beam patterns within a +45° and−45° coverage in the azimuth plane. In this configuration,N_(PAA)<N_(AP)=N_(TRX)<N_(AE).

FIG. 9 illustrates a PAA 902 connected to an RF chain 904 and a PAA 906connected to an RF chain 908. For example, PAAs 902, 906 may havededicated RF chains. As illustrated in FIG. 9 , the number of phaseantenna arrays, N_(PAA), the number of antenna ports N_(AP), the numberof RF chains (TRX) N_(TRX), and the number of antenna elements N_(AE)may be related as: N_(PAA)=N_(AP)=N_(TRX)≤N_(AE). Such an example mayallow a spatial independence between the two simultaneous beams byplacing the PAAs 902, 906 at different orientations, e.g., in theazimuth plane. An aligned PAA arrangement may provide an aggregatedlarger coverage compared to the configuration in FIG. 8 . The antennaconfiguration may be fully digitized and may be comparable to theconfiguration shown in FIG. 7 , e.g., when the number of TRX is equal tothe number of antenna elements (e.g., one RF chain per antenna element).

In an example, N_(DATA)≤N_(TRX)≤N_(AE). When N_(DATA)=N_(TRX)=1, anmWTRU may have a single-beam configuration and may operate one beam at atime. The mWTRU beamforming may form a narrow beam pattern, asillustrated in FIG. 10 , at an angular direction, e.g., the strongestangular direction, e.g., a LOS path estimated from beam measurement.

The mWTRU may form a broad beam pattern having a wide main lobe, anexample of which is illustrated in FIG. 11 , to cover a range ofcontinuous angular directions including strong and weak ones in between.The antenna gain may be reduced when forming a broad pattern, and thelink budget may become worse.

The mWTRU may adaptively form a beam pattern with multiple distinctstrong lobes, an example of which is illustrated in FIG. 12 , to receiveat two or more different incoming angular directions. Multiple transmitbeams may be directed, for example, at multiple strong specularreflection paths to take advantage of spatial diversity. The forming ofthis beam pattern may reduce the antenna gain compared to a narrow beampattern. The adaptive beam pattern may use a beamforming algorithm tohave continuous steering and forming capability to dynamically adjustthe beam pattern in response to the estimated channel conditions.

When N_(DATA)=1<N_(TRX), for example, when N_(TRX)=2, an mWTRU may havetwo simultaneous beam patterns and the beam patterns may be differentand used for different applications. The mWTRU may place two narrow beampatterns at different angular incoming directions to utilize spatialdiversity and mitigate the blockage effect and/or weak LOS condition.This may facilitate beam combining. The mWTRU may place two narrow beampatterns at different angular incoming directions and may apply a fastbeam switching mechanism when one beam's channel conditions deteriorate,e.g., quickly. The mWTRU may form a narrow beam and a broad beam fordifferent applications. For example, the narrow beam may be used fortraffic, and the broad beam may be used for control signaling.

When 1<N_(DATA)=N_(TRX), the transmission may apply MIMO to increase thecapacity, for example, in high SNR channel conditions. The mWTRU mayplace two narrow beam patterns at different angular incoming directionsto receive two data streams. The mWTRU analog beamforming algorithms mayinclude fixed codebook-based beamforming and/or eigenvalue-basedbeamforming.

In fixed codebook-based beamforming, a grid of beams may include a setof fixed beams. A beam may be formed by the mWTRU applying a beamformingvector v chosen from a predefined codebook v∈{v₁, v₂, v₃ . . . v_(N)},where N may denote the number of fixed beams. Each vector may includepre-calibrated phase shifts for phase shifters and may represent ananalog beam direction, e.g., a beam. The number of beams may depend onthe half-power-beam-width (HPBW) and desired coverage.

Eigenvalue-based beamforming may involve a precoding appliedeigenvalue-based weight vector based on short-term channel information.The algorithm may perform well in scenarios with increased multipath andhigh angular spread and low mWTRU mobility. Such beamforming may providethe adaptive beamforming capability to track channel conditions.

Small cell mmW base station (SCmB) beamforming schemes may include fixedbeam, adaptive beamforming, e.g., codebook-based and non-codebook-based,and classical beamforming, e.g., DoA estimation. A scheme may usedifferent procedures. For example, the DoA estimation may use a smallerangular spread, and an mWTRU may transmit an LTE band uplink referencesignal for AS range estimation to provide DoA accuracy. The fixed beamsystem may use beam cycling and beam switch mechanisms.

A legacy (e.g., LTE) WTRU antenna configuration may have anomnidirectional radiation pattern with an antenna gain of 0 dBi. Suchantenna configuration may be used in RAN1/RAN4 system and linksimulation for evaluation of various technologies, including, e.g.,release 12 (R12) 3D MIMO/beamforming. The WTRU antenna beam may be fixedat a wide beam width, e.g., 120° with a maximum 3 dBi gain in elevationand 0 dBi in azimuth. The WTRU may receive a downlink beamformedphysical downlink shared channel (PDSCH) with the help of a physicaldownlink control channel (PDCCH) carrying information including antennaport, number of layers, scrambling identity, etc. The associateddemodulation reference signal (DMRS) may be WTRU-specific and may bebeamformed along with data symbols.

SCmB and mWTRU may form highly directional and narrow beam patterns toprovide beamforming gain, for example, to overcome the significant pathloss experienced by the mmW channels and to meet the link budget for theSCmB deployment. The mmW control information may be transmitted andreceived within a beam pair. The dedicated nature of the controlsignaling due to the spatial isolation may involve a different controlsignaling and data scheduling than may be used in some LTE systems.Systems, methods, instrumentalities may be provided to receive mmWscheduling information in paired mmW narrow beam patterns, e.g., fromnarrow-beam-common PDDCCH and/or dedicated PDDCCH to PDDDCH.

An SCmB and one or more mWTRUs may operate in LTE and mmW frequencybands. Such SCmB and mWTRUs may use the mmW frequency band for data,e.g., transmit data in mmW narrow beam patterns. Such SCmB and mWTRUsmay apply a cross-system scheduling, e.g., schedule mmW data via LTEdownlink channels. The mmW DCI carried in LTE channels may includedynamic per-TTI scheduling information.

Control signaling and scheduling design may take into account multipledesign issues, including the timing difference between the two systems,the inequality of TTI lengths of the two systems, and/or the LTEscheduling mechanism. Procedures may use LTE channels to schedulePDDDCH, e.g., from PDCCH/EPDCCH/PDSCH to PDDDCH.

Carrying dynamic per-TTI mmW DCI in LTE channels may reduce cross-systemscheduling efficiency due to operation difference between the twosystems. To better utilize the LTE channel resources, the SCmB may useLTE channels for relatively static mmW DCI and may transmit PDDCCH inmmW narrow beams to convey the dynamic per-TTI mmW DCI. The design mayuse coordination and sequencing of the mmW DCI over different LTEchannels and PDDCCH. Procedures may apply such a multi-stagecross-system scheduling, e.g., from PDCCH/EPDCCH/PDSCH to dedicatedPDDCCH to PDDDCH.

An SCmB may form an mmW broad beam pattern to carry control information(e.g., layer one (L1) control information) for mWTRUs associated with anmmW cell or sector. mWTRU receive beam may receive a downlink broad beamin a configured beam position. A broad beam may carry controlinformation for one or more users. The signaling associated with controlinformation may be multiplexed. Systems, methods, instrumentalities maybe provided to an mWTRU to detect and/or receive control signaling froma downlink mmW broad beam pattern, e.g., broad beam PDDCCH to PDDDCH.

Millimeter wave (mmW) downlink control information (mDCI) may includemWTRU beam scheduling and dynamic per-beam pair structure configurationinformation. mDCI signaling may carry control information that may beused for the downlink mmW data scheduling, e.g., information used for anmWTRU to locate, demodulate, and/or decode the PDDDCH.

Millimeter wave downlink control information (mDCI) may include transmitand receive beam scheduling information. Such scheduling information maybe used for an mWTRU to identify transmit and/or receive beam to be usedfor the scheduled data transmission. The information may be signaled,for example, using an antenna port number or a beam identificationnumber or may be derived, for example, from a code assignment, such asBSRS index. An SCmB scheduler may assign mmW data to an mWTRU, forexample, based on channel measurements specific to a receive beam and aLTE channel measurement. For example, channel quality indication (CQI)may not be associated with a receive beam that is used for themeasurement. The network at the transmitter may have informationregarding the available options for the receive beam. Since the receiverorientation may alter, a receiver beam may be specified in globalcoordinates rather than relative to the mWTRU orientation, for example,by compensating via use of gyros, compasses, and the like. Thisbeam-specific scheduling information may be carried in a common PDDCCHor a dedicated PDDCCH or an LTE channel, for example, depending on thecontrol signaling design.

Millimeter wave downlink control information (mDCI) may include dynamicframe structure configuration information. The time slot or subframeconfiguration for downlink and uplink allocation may be altered (e.g.,dynamically altered) to adapt to the downlink and uplink traffic load.This configuration may be per beam pair, e.g., between an SCmB and anmWTRU. A plurality of (e.g., two) beam pairs may use different timedivision duplex (TDD) configurations without downlink-to-uplink and/oruplink-to-downlink interference between the beam pairs, for example,because of spatial isolation that may be provided due the narrow beampairing.

Millimeter wave downlink control information (mDCI) may includescheduling duration information. FIG. 13 illustrates examples of dynamicpredictive scheduling per beam pair (e.g., between SCmB transmit (Tx)Beam 1 and mWTRU Rx Beam 3, and between SCmB Tx Beam 2 and mWTRU Rx Beam2). As illustrated in FIG. 13 , the number of mmW TTIs scheduled in aPDDCCH may vary, for example, using predictive scheduling. The SCmB mayconfigure (e.g., predictively configure) multiple consecutive TTIs in abeam pair to be scheduled at one time. The configuration of multipleconsecutive TTIs may depend on the channel condition. For example, incase of SCmB Tx Beam 1/mWTRU Rx Beam 3 beam pair, for sub-frame N 1302,three consecutive TTIs (1304) may be configured, whereas, in case ofSCmB Tx Beam 2/mWTRU Rx Beam 2 beam pair, for sub-frame N 1302, fourconsecutive TTIs (1306) may be configured. The number of the consecutiveTTIs may be conveyed in the dynamic frame structure configurationinformation carried in the dedicated PDDCCH. For example, a schedulingvalidity period value indicating the number of consecutive TTIs. Themultiple TTI configuration may save signaling overhead. Because of theexclusive nature of the dedicated PDDCCH, the interference betweendifferent mWTRUs may be eliminated.

Millimeter wave downlink control information (mDCI) may include PDDDCHfrequency resource allocation information. For example, the PDDDCHfrequency resource allocation may include location of the frequencyresource that the PDDDCH applies, e.g., RBs in the OFDM-based system orcarrier indicator in the SC-based system. The number of bits used maydepend on one or more factors including the system bandwidth, schedulinggranularity, etc. Localized or distributed allocation may be considered.The mmW channel within the narrow beam may not have as much frequencyselectivity as the distributed allocation may exploited, e.g., as in theLTE channel. The DMRS associated with the PDDDCH may be placed in theallocated region according to a pre-standardized pattern.

Millimeter wave downlink control information (mDCI) may include PDDCCHfrequency resource allocation information. For example, the PDDCCHfrequency resource allocation information may include the location ofthe frequency resource that the PDDCCH applies. This may be similar toPDDDCH frequency resource allocation when PDDCCH and PDDDCH aretime-multiplexed in an mmW narrow beam as shown in FIG. 6 . PDDCCH maybe placed separately in an mmW broad beam. The allocation of PDDCCH maybe pre-standardized without explicit real-time signaling in a similarway as how PDCCH operates.

Millimeter wave downlink control information (mDCI) may include codeassignment information. For example, the code assignment information mayinclude configuration of BSRS sequence index or scrambling code indexthat an mWTRU may use to detect and/or demodulate the BSRS and/or datatransmission. The scrambling code may be used on PDDDCH or PDDCCH.

Millimeter wave downlink control information (mDCI) may include carrierindicator information. Within a beam pair, the mmW data transmission mayuse carrier aggregation. An mWTRU may receive scheduling informationapplicable to a different SC-based or OFDM-based carrier than the onethat carries the control information.

Millimeter wave downlink control information (mDCI) may includeinformation associated with the modulating and coding scheme, such asthe transport format of the data transmitted in the scheduled TTI,including information relating to a coding rate and modulating scheme. Aset of predefined MCS values corresponding specific coding rates andmodulation schemes may be used, for example, in the form of an MCStable.

Millimeter wave downlink control information (mDCI) may include dataindication information that may indicate whether the scheduled TTI has anew data transmission or a retransmission. mDCI may include redundancyversion information that may identify which redundancy version of aretransmission is carried in the scheduled TTI. The redundancy versionmay be applied in an incremental redundancy retransmission scheme.

Millimeter wave downlink control information (mDCI) may includeinformation relating to the number of layers. An mmW data transmissionmay include multiple layers to utilize multiple input multiple output(MIMO) application along with beamforming. A mWTRU may de-map the datafrom different layers based on this information.

Millimeter wave downlink control information (mDCI) may include achannel state information request. The SCmB may request channel stateinformation, including channel quality indicator (CQI), precoding matrixindicator (PMI), rank indicator (RI), etc. The CQI measurement may bebeam specific and based on BSRS. The SCmB may transmit specific CSI-RSin the frequency allocation in the beam. Such a beam may not be used forthe data or for scheduling purpose. The CQI may be wide band or subband.

Millimeter wave downlink control information (mDCI) may include abeam-specific measurement request. The SCmB may request a qualitymeasurement specific to a certain transmit beam for scheduling purpose.An associated beam measurement occasion may be configured explicitly inthis request or may be implicitly indicated based on configurationssignaled beforehand, for example, in SIB. The beam specific measurementmay be an analog measurement as opposed to a digital signal-to-noiseratio (SNR)-based CQI measurement. For example, an mWTRU may detectenergy at a specific frequency resource to determine the strength of abeam. The beam quality measurement may be a layer 1 (L1) measurement andfeedback mechanism that provide real-time beam-specific information.

Millimeter wave downlink control information (mDCI) may include mmW UCIresource allocation. The uplink resource may be allocated implicitly formmW uplink channel state information or other reporting of measurement.The association between a downlink mmW transmission and the UCI resourceallocation may be realized in, for example, the specific beaminformation, frequency resource allocation, code assignment, etc.

Certain scheduling information, such as beam scheduling, may be providedfor long-term. The decoding of the long-term scheduling information maybe periodic or triggered by certain predefined events. These events mayinclude, for example, degradation of beam strength or SINR, a higherlayer command, and/or consistent measurement of a better beam pair forthe mmW sector.

Periodic and configured mWTRU receive narrow beam cycling may be used todetect mmW sector BSRS. Such receive beam cycling may also be used toread common PDDCCH for mmW segment identity for two-dimensionalbeam-specific measurement of beam signal strength or beamsignal-to-interference-plus-noise ratio (SINR) metrics.

Millimeter wave downlink control information (mDCI) transmission mayvary, e.g., based on the control signaling and/or scheduling proceduredesign. The control signaling and scheduling procedure design may bebased on the transmit beam configuration and/or the receive beamconfiguration, the cooperation between LTE and mmW systems, etc.

Transmission of one or more DCI parameters may be conveyed, for example,depending on the system design. Certain DCI parameters may betransmitted differently from others and may have different applicationin each scheduling instance.

Millimeter wave downlink control information (mDCI) transmission for anmWTRU may be carried out in a physical layer channel or sequentially inmultiple (e.g., two) physical layer channels. For example, a dedicatedPDDCCH may carry per-TTI scheduling information including MCS. Theper-TTI scheduling information may be applied to an associated PDDDCHwithout beam specific information. A common PDDCCH may be used by anmWTRU to identify the beam and extract the dedicated PDDDCH. A portionof the mmW DCI may be carried in higher layer signaling.

Systems, methods, and/or instrumentalities provided here related to mmWbeam transmission may apply to the mmW system. FIG. 14 illustrates anexemplary mmW system with fixed narrow beam pattern. As illustrated inFIG. 14 , an SCmB 1406 may overlay an mmW coverage onto the LTE smallcell coverage 1402, e.g., provided by an omnidirectional antenna. Thesmall cell coverage 1402 may be located within a broad beam system,e.g., a macro LTE sector 1404. The mmW coverage may be implemented byusing, for example, six mmW PAAs. Each of the PAAs may be used with oneor more narrow beams of, for example, 10° horizontal beam width. Thenumber of simultaneous SCmB beams within an mmW sector may be limiteddue to hardware complexity and cost. For example, six beam directionsthat may be considered as a segment, when an SCmB operates a fixed beamsystem with a narrow beam of 10° half power bandwidth (HPBW) in a mmWsector. The SCmB may cycle the narrow beam in the segments according tocertain configurations, including pattern, periodicity, power, etc.

As illustrated in FIG. 14 , mWTRU 1408 may attach to SCmB 1406 using anLTE CS procedure, e.g., based on the best LTE cell. mWTRU 1408 andreceive mmW-specific configuration, e.g., via an SIB. The receivedconfiguration may include configuration regarding timing offset betweenan LTE downlink reference and mmW subframe timing. The mWTRU 1408 mayalign the mmW reception using the timing offset and the detected LTEdownlink reference timing from primary synchronization signal (PSS)and/or secondary synchronization signal (SSS) and common referencesignal (CRS).

The received configuration may include configuration regarding mmWsector BSRS code indices that may identify each mmW sector. For example,the BSRS may use a pseudorandom sequence, such as a Zadoff-Chu (ZC)sequence with good auto- and cross-correlation properties and with goodperformance against timing and frequency offsets. In the case of a ZCsequence, sector sequences may be generated based on a ZC base sequencespecific to the SCmB.

The received configuration may include configuration regarding mmWsegment BSRS code indices. Such configuration may identify an mmWsegment within an identified sector. The mmW segment identity may beencoded in a control field following BSRS, for example, using three bitsto represent up to eight identities in a common PDDCCH.

The received configuration may include configuration regarding afrequency resource that may be used for the sector BSRS, segment BSRS,and/or the common PDDCCH within the narrow beam. The receivedconfiguration may include configuration regarding subframe, periodicity,transmission pattern, and/or other configuration parameters of thesector, segment BSRS, and/or the common PDDCCH.

The received configuration may include configuration regarding timedomain resources, for example, symbol location, time slot or subframe ofthe BSRS, and dedicated PDDCCH transmission within the narrow beam.

The received configuration may include configuration regardingperiodicity, power, and/or a pattern of the SCmB beam cycling over themmW segments within an mmW sector. For example, the system frame number(SFN) in which the downlink beam is at a sector and the duration interms of subframes at the position may be signaled to mWTRUs. The powerof the beam may be used to estimate the path loss of a segment. In anSFN cycle, an SCmB may dedicated a number of consecutive subframes tocycle over the segments for beam-specific measurement.

The received configuration may include configuration regardingperiodicity, pattern, and/or other configuration parameters of the mWTRUbeam cycling. The received configuration may include configurationregarding the common PDDCCH transport configuration parameters, forexample, the information payload and transport format of the controlfields carried in the channel.

One or more mmW BSRS configuration parameters may be applicable tomultiple mmW sectors of SCmBs. An mWTRU may detect mmW sectors that arenot co-located with the SCmB to which the mWTRU is attached.

An mWTRU may perform a cycling procedure to provide beam measurement atan mWTRU receive beam position for scheduling or other purposes. ThemWTRU may form an mmW narrow receive beam according to the cyclingpattern, periodicity, and/or other configuration parameters. The otherconfiguration parameters may be determined according to the mWTRUcapability and/or signaling from the network.

The sector BSRS and segment BSRS may be correlated. The sector BSRS andsegment BSRS may be detected according to the BSRS configuration. Theduration at an mWTRU receive beam direction may be derived from theduration of the SCmB beam at a segment. For example, with the durationof an mWTRU receive beam direction, the SCmB may have a cycling of beamsover the segments within an mmW sector. The mmW sector and segment todetect and measure at a receive beam direction may be requested and/orconfigured by the network. For example, an mWTRU may be configured touse a subset of receive beam directions and mmW segments for subsequentmeasurement. As illustrated in Table 2 below, the network may requestand configure beam-specific measurements for the beam pairs whosemeasurement metric is higher than 15 (e.g., as represented by boldentries).

TABLE 2 mWTRU Rx Beam\Segment 1 2 3 4 5 6 1 1 1 1 2 1 1 2 5 6 6 7 6 6 312 18 22 23 22 17 4 10 12 15 16 11 9 5 4 5 6 6 6 5 6 1 1 2 1 1 1

The mWTRU may synchronize in timing and frequency with the strongestBSRS that may belong to its associated SCmB. The mWTRU may synchronizewith the strongest BSRS from a non-co-sited mmW sector, e.g., if thereis no BSRS strong enough to be detected. The mWTRU may report zero or nometric at this receiver beam direction, e.g., if no BSRS is detected.

The mWTRU may demodulate and decode the common PDDCCH. The mWTRU mayobtain the mmW segment identity. The common PDDCCH may apply apredefined transport format. The common PDDCCH reading may involve thesegment identity field that may be accessible for all mWTRUs.

The segment identity may not be explicitly encoded in a data format, butmay be embedded in an mmW segment reference signal that may be of thesame type as the mmW sector BSRS. The mWTRU may correlate the segmentBSRS. The mWTRU may identify the segment BSRS and synchronize furtherwith the segment BSRS. The mmW sector and segment BSRS may be aligned intime according to a predefined relationship. The sequence generation maybe based on the sector and segment identifiers assigned by the network.

The mWTRU may denote the measured signal strength (e.g., analogmeasurement) and/or SNR of the identified mmW sector and/or segment forthis specific receive beam. The metric may be quantized to integervalues according to a predefined table. This information may be on aper-receive-beam basis as illustrated in Table 2 with a beamconfiguration of six segments per mmW sector and six receive beampositions of an mWTRU. The example may assume a metric table rangingfrom 1 (e.g., minimum SINR or beam strength) to 32 (e.g., maximum SINRor beam strength).

The mWTRU may report the measured mmW segment metric at an mWTRU receivebeam direction to the network. This receive beam cycling and measurementof an mmW sector and segment may provide the network with theinformation for mmW sector association and data scheduling. Thereporting may include the beam-specific measurement results asillustrated in Table 2.

The mWTRU may report the measurement metric whose values are above apreconfigured threshold. For example, Table 3 illustrates athreshold-based measurement with a threshold of 10. The reporting mayonly include beam-specific measurements of the mWTRU receive beam 3 and4 and for receive beam 4 only mmW segments 2 to 5.

TABLE 3 mWTRU Rx Beam\Segment 1 2 3 4 5 6 1 2 3 15 18 22 23 22 20 4 1215 16 11 5 6

A periodic and selectively-configured beam cycling and measurement mayprovide input to the scheduling procedure. The mmW DCI may include beamallocation information. The scheduled mWTRU may place the receive beamaccordingly and may synchronize with the BSRS without searching for atransmit beam.

An mmW narrow-beam-common PDDCCH may be used for long-term scheduling ofan mWTRU receive beam. A dedicated PDDCCH may be used for per-TTIdynamic scheduling of PDDDCH. The mmW narrow beam pattern transmitted byan SCmB may carry PDDCCH and PDDDCH.

Per-TTI mmW data scheduling information may be carried in a dedicatedPDDCCH. The transmit and receive beam scheduling information may becarried in a common PDDCCH. The transmit and receive beam schedulinginformation may be intended for one mWTRU per beam. An mWTRU may detectits beam scheduling information of the common PDDCCH using an WTRUspecific identity information, e.g., international mobile subscriberidentity (IMSI)/cell radio network temporary identifier (C-RNTI)/mmWradio network temporary identifier (mmW-RNTI) scrambled cell-specificreference signal (CRS) and/or payload may be scrambled with the identityinformation as provided above.

An mWTRU may begin with a periodic or requested beam cycling asdisclosed herein. Configuration parameters may be used for the initialbeam acquisition, such as transmit beam cycling periodicity, number oftransmit beams, transmit beam BSRS code index, etc.

The mWTRU may cycle its coverage and may detect transmit beams, e.g.,mmW segments, at a receive beam direction (e.g., each receive beamdirection). The transmit beam that carries the data transmission mayhave mWTRU-specific information in the common PDDCCH, e.g., the mWTRU'sC-RNTI, mmW-RNTI, or other identity. The mWTRU may detect a transmitbeam at a receive beam direction. The mWTRU may decode the commonPDDCCH. The mWTRU may detect the scheduling and may start the datatransmission. The per-TTI scheduling data may be obtained from thededicated PDDCCH, as illustrated in FIG. 15 . The mWTRU may receivetransmit and/or receive beam scheduling information in the common PDDCCHand the dynamic per-TTI scheduling information in the dedicated PDDCCH.

As illustrated in FIG. 15 , a mWTRU (e.g., mWTRU1) may form an mmWnarrow receive beam. The mWTRU may form an mmW narrow receive beamaccording to the cycling pattern, periodicity, and/or otherconfiguration parameters. The other configuration parameters may bedetermined according to the mWTRU capability and/or signaling from thenetwork. The receive beam forming may be based on an event-triggeredmonitoring of the common or dedicated PDDCCH for upcoming schedulinginstances or a periodic cycling for measurement and schedulingmonitoring.

The mWTRU may correlate and detect sector BSRS. The mWTRU maysubsequently segment BSRS according to the BSRS configuration. Theduration at an mWTRU receive beam direction may be derived from theduration of the SCmB beam at a segment. For example, with the durationof an mWTRU receive beam direction, the SCmB may have a cycling of beamsover the segments within an mmW sector.

The mWTRU may synchronize in timing and frequency with the strongestBSRS that may belong to its associated SCmB. If no such BSRS is found,the mWTRU may synchronize with the strongest BSRS from a non-co-locatedmmW sector.

The mWTRU may demodulate and decode the common PDDCCH (e.g., SCmB TxBeam 1 common PDDCCH 1502 related to mWTRU1). The mWTRU may obtain themmW segment identity. The common PDDCCH may apply the predefinedtransport format. Segment identity in the common PDDCCH may be read byone or more mWTRUs, e.g., all mWTRUs.

The mWTRU may correlate and detect the segment BSRS and may synchronizewith the detected segment BSRS.

The mWTRU may demodulate and decode the common PDDCCH or the dedicatedPDDCCH to determine whether the mWTRU is scheduled for a segment. ThemWTRU may also determine the identification of the received beam themWTRU may use. The field of the common PDDCCH carrying the informationassociated with the identification of the received beam and whether amWTRU is scheduled for a segment may be encoded with the scheduledmWTRU's identity, for example, C-RNTI, mmW-RNTI, or IMSI. The encodingmay be realized in CRC scrambling and/or payload scrambling.

The mWTRU may form the schedule receive beam at the scheduled directionand may demodulate and decode the dedicated PDDCCH (e.g., dedicatedPDDCCH 1504) for the dynamic per-TTI scheduling information such as MCSand NDI. The resource allocation of common and dedicated PDDCCH may besignaled by the network via higher layer signaling, for example, insystem information block (SIB).

The mWTRU may read the validity period for a scheduling instance and mayapply the validity period accordingly to consecutive mmW TTIs. Asillustrated in FIG. 15 , dedicated PDDCCH (e.g., dedicated PDDCCH 1506related to mWTRU2) may carry scheduling information that may beapplicable to a number of consecutive mmW TTIs 1508. The mWTRU maydemodulate and decode the associated PDDDCH (e.g., 1508) with the helpof DMRS according to the scheduling information received in thededicated PDDCCH.

Dedicated PDDCCH only scheduling of PDDDCH may be provided. FIG. 16illustrates and example of such scheduling. As illustrated in FIG. 16 ,the beam scheduling information may be included in dedicated PDDCCH(e.g., dedicated PDDCCH scheduling 1602 for mWTRU1 and dedicated PDDCCHscheduling 1604 for mWTRU2) in an mmW subframe n 1606. The datascheduling may not involve the common PDDCCH. The beam schedulinginformation may be repeated, e.g., when an mWTRU may continue datatransmission within a same beam pair.

The scheduling information used for a TTI within a transmit/receive beampair, based on channel condition, may be suitable for one or more TTIs(e.g., consecutive TTIs). One dedicated PDDCCH may be used to schedule anumber of consecutive PDDDCHs, e.g., TTIs. This type of dynamic framestructure may be per beam pair and may change from subframe to subframe,as illustrated in FIG. 13 .

The mmW DCI in the dedicated PDDCCH may carry a control field toindicate the validity period in terms of a number of TTIs during whichthe same scheduling information may apply. The mWTRU may not attempt todecode the dedicated PDDCCH in the subsequent TTIs, as the entire TTIlength may be occupied by the PDDDCH. This may save control signalingoverhead, and such configuration may vary in a beam pair and due to thespatial isolation between beam pairs, no interference may arise fromthis configuration. The validity period may vary depending on thechannel condition of a beam pair.

LTE physical downlink control channel (PDCCH) and/or enhanced PDCCH(EPDCCH) may be used for long-term scheduling of an mWTRU beam and mmWPDDDCH over multiple mmW TTIs. DCI fields may be utilized to indicateassociated TTI numbers. The mmW narrow beam pattern transmitted by aSCmB may carry PDDDCH, e.g., and no common or dedicated PDDCCH. The mmWdata may be scheduled using LTE L1 channels.

An LTE DCI format may be used to carry the mmW DCI information. The LTEDCI format may include mDCI fields as disclosed herein. The mDCI fieldsmay include one or more of: transmit and receive beam scheduling,dynamic frame structure configuration, scheduling duration, PDDDCH andits DMRS frequency resource allocation, PDDDCH DMRS code assignment,carrier indicator, modulation and coding scheme, new data indication,redundancy version, number of layers, channel state information request,beam-specific measurement request, or mmW UCI resource allocation.

The LTE DCI may include a scheduling TTI number. The mmW TTI length maybe significantly less than the LTE TTI length of 1 ms. A PDCCH mayschedule a number of mmW TTIs. Predictive scheduling may be applied toschedule consecutive TTIs. In either case, the LTE DCI may include afield for the scheduling TTI number to associate the schedulinginformation with an mmW TTI to be scheduled.

The LTE DCI may include mmW UCI processing information. The network mayconfigure how to process the multiple ACKs/NACKs associated with thescheduled PDDDCH transmission, the beam specific measurement, and/orother mmW uplink control information per mmW TTI. Such information maybe processed (e.g., bundled and/or multiplexed) by an mWTRU, andtransmitted in LTE physical uplink control channel (PUCCH). The mmW UCIprocessing information may be used to signal the type of processing themWTRU may use.

An mWTRU may monitor PDCCH, e.g., as specified in LTE standards. ThemWTRU may detect the mmW DCI carried in its PDCCH using its C-RNTI andmay decode the scheduling information. The mWTRU may receive one set ofscheduling information for an mmW TTI. The timing offset between thedownlink LTE reference subframe timing and mmW subframe timing may allowadequate time to decode the mmW DCI.

FIG. 17 illustrates an example of PDCCH scheduling of PDDDCH. Asillustrated in FIG. 17 , an mWTRU (e.g., mWTRU1) may form the receivebeam according to the scheduled receive beam information and may alignthe mmW subframe receiving timing according to the LTE subframe starttiming and a predefined timing offset. The decoded PDCCH 1706 in LTEsubframe N 1702 may be applied in mmW subframe n 1704. N may be equal orunequal to n. N may equal n, for example, when both LTE subframe and mmWsubframe are 1 ms. As illustrated in FIG. 17 , one LTE PDCCH 1706 mayschedule multiple mmW TTIs, for example, depending on the length of themmW TTI. For example, mmW TTI may be 100 μs and one mmW sub-frame mayinclude 10 mmW TTIs. Accordingly, one PDCCH may schedule up to 10 mmWTTIs.

The mWTRU may correlate and detect an mmW sector BSRS and maysubsequently segment BSRS according to the scheduled BSRS configuration.The mWTRU may subsequently synchronize its timing and frequency based onthe reference signals.

The mWTRU may demodulate and decode a scheduled TTI according to the TTInumber and associated scheduling information in the mmW DCI. Asillustrated in FIG. 17 , the mWTRU mWTRU1 may use the schedulinginformation from one PDCCH 1706 in LTE subframe N 1702 to receive TTI 21708 and TTI 6 1710 in mmW subframe n 1704. The mWTRU mWTRU2 may receivescheduling information in TTI2 1712 and TTI9 1714.

The mWTRU may read the validity period for each scheduling instance andapply the validity period accordingly to consecutive mmW TTIs. An LTEPDCCH may carry, for example, multiple scheduling information eachapplicable to a number of consecutive mmW TTIs. FIG. 18 illustrates anexample of PDCCH 1808 (e.g., in LTE subframe N 1802) scheduling ofPDDDCH over multiple TTIs (e.g., in mmW subframe n 1806). As illustratedin FIG. 18 , an mWTRU mWTRU1 may receive one set of schedulinginformation 1804 for TTIs TTI2, TTI3 and TTI4. The LTE PDCCH 1808 in LTEsubframe N 1802 may carry two sets of scheduling information for foursets of mmW TTIs. A similar procedure may be applied by an mWTRU whenenhanced PDCCH (EPDCCH) is applied to schedule the mmW PDDDCH.

FIG. 19 illustrates an example of EPDCCH scheduling of PDDDCH. Asillustrated in FIG. 19 , first EPDCCH 1904 (e.g., in LTE subframe N1902) may carry scheduling information 1908 of PDDDCH related to mWTRU1(e.g., in mmW subframe n 1912). As illustrated in FIG. 19 , a secondEPDCCH 1906 may carry scheduling information 1910 of PDDDCH related tomWTRU2.

LTE millimeter wave physical downlink control channel (mmPDCCH) dynamicper-TTI scheduling of mWTRU beam and PDDDCH may be provided. The per-TTIscheduling may be provided by PDCCH or detected by blind-decoding. Adownlink LTE control physical channel, mmPDCCH, may transmit mmWscheduling information dynamically on a per-mmW-TTI basis, for example,to cope with the impact of the inequality of LTE and mmW TTI. An mmPDCCHmay be transmitted at each downlink LTE symbol location that has aone-to-one mapping to the mmW TTI to be scheduled. The mmPDCCHtransmitted in symbol N may schedule the PDDDCH transmission in timeslot N of the upcoming mmW subframe.

In an LTE downlink frame structure there may be thirteen symbollocations among which two or three symbols may be used for PDCCH. An LTEsubframe may have 10 mmPDCCH for one mWTRU. Multiple mmPDCCHs may belocated at the same symbol location for the scheduling of multiplemWTRUs.

The mDCI disclosed herein may be encoded in the mmPDCCH. The mmPDCCH mayhave dedicated resources for its mWTRU that may be scheduled by PDCCH orthat may have a multiplexed structure that may involve blind decoding ofmWTRUs.

For an mWTRU to decode an mmPDCCH, an LTE DCI specific to mmPDCCH may beused. The DCI may be used to schedule an L1 control channel. The mmPDCCHDCI per mWTRU may include, for example, a symbol location, a frequencyresource allocation (e.g., PRB assignment), a modulation and codingscheme (e.g., may be predefined and not included in mmPDCCH DCI), ademodulation reference signal configuration, and/or an uplink millimeterwave physical uplink control channel (mmPUCCH) configuration (e.g., anassociated mmW UCI transmission). The mDCI carried in the mmPDCCH mayapply the fields disclosed herein.

FIG. 20 illustrates an example of dedicated mmPDCCH scheduling ofPDDDCH. An mWTRU may monitor PDCCH 2004 (e.g., in an LTE sub-frame N2002). As illustrated in FIG. 20 , in a dedicated mmPDCCH (e.g., mmPDCCH2006 related to mWTRU1), the mWTRU mWTRU1 may detect mmPDCCH specificLTE DCI carried in its PDCCH 2004 using its C-RNTI and may decodeinformation for receiving its upcoming mmPDCCH 2006. The mmPDCCHspecific LTE DCI may include mmPDCCH symbol location 2008, frequencyresource, transport format, and/or other configuration parameters. ThemmPDCCH 2006 may carry scheduling information 2010 related to PDDDCH2012 of mWTRU1 (e.g., in subframe n 2014).

The mWTRU may locate and decode the mmPDCCH in the schedule symbollocation of the same LTE TTI. As the mWTRU signaled by the PDCCH (e.g.,only the mWTRU signaled by the PDCCH) may read the mmPDCCH, no blinddecoding may be necessary at the symbol location. The mmPDCCH may carrymDCI, including, for example, the beam allocation, BSRS, PDDDCH resourceallocation, etc.

FIG. 21 illustrates an example of multiplexed mmPDCCH scheduling ofPDDDCH. As illustrated in FIG. 21 , in a multiplexed mmPDCCH, an mWTRUmay blind decode symbol location and frequency resources, e.g., todetermine if its mmPDCCH is present for mmW scheduling. An mWTRUidentity, such as C-RNTI, mmW-RNTI, or IMSI may be used to identify themmPDCCH. The mmPDCCH may be multiplexed between multiple mWTRUs and maybe transmitted over a frequency allocation with configuration signaledover RRC signaling to mWTRUs. mWTRUs may perform blind decoding at theconfigured symbol location and frequency resources according to theirsignaled mmPDCCH configuration. The mWTRU may demodulate and decode themmPDCCH, e.g., if the mmPDCCH is detected in the blind decoding. ThemWTRU may read mDCI information from the mmPDCCH.

In the dedicated mmPDCCH approach and/or the multiplexed mmPDCCHapproach, the mWTRU may demodulate and decode one set of schedulinginformation mDCI for the associated mmW TTI. The timing offset betweenthe downlink LTE reference subframe timing and mmW subframe timing mayallow adequate time to decode PDCCH and mmPDCCH. The mWTRU may form areceive beam according to the scheduled receive beam information and mayalign an mmW subframe receiving timing according to the LTE subframestart timing and a predefined timing offset. The decoded mmPDCCH in LTEsubframe N may be applied in mmW subframe n. In the example shown in theFIG. 20 , the number of the symbol location where the mmPDCCH is locatedin the LTE subframe may be the same as the number of the associated mmWTTI in the mmW subframe.

The mWTRU may correlate and detect mmW sector BSRS and may segment BSRSaccording to the scheduled BSRS configuration. The mWTRU may synchronizeits timing and frequency based on the reference signals. The mWTRU maydemodulate and decode a scheduled mmW TTI. As illustrated in FIG. 20 ,mWTRU mWTRU1 mmPDCCH at symbol locations 2 2008 and 6 2020 of LTEsubframe N 2002 may be applied to decode the mmW transmission in mmW TTI2 2012 and 6 2022 in mmW subframe n 2014. The mWTRU WTRU2 mmPDCCH atsymbol locations 2 2016 and 9 2018 may be applied to schedule the samemmW TTIs. As illustrated in FIG. 20 , WTRU2 mmPDCCH 2016 may usepredictive scheduling and the validity period field in mDCI to schedulemmW TTI 2, 3, and 4 with one mmPDCCH.

FIG. 21 illustrates an example of multiplexed mmPDCCH scheduling ofPDDDCH. As illustrated in FIG. 21 , when the mmPDCCH applies blinddecoding, mWTRU1 and mWTRU2 mmPDCCHs may be multiplexed in symbols 2, 6,and 9. As illustrated in FIG. 21 , mWTRU mWTRU1 mmPDCCH at symbollocation 2 2104 of LTE subframe N 2102 may be used to decode the mmWtransmission in mmW TTI 2 2108 of the mmW subframe 2106.

LTE PDCCH, EPDCCH, MAC control element(s), and/or mmPDCCH may be usedfor long-term scheduling of an mWTRU beam. Dedicated PDDCCH may be usedfor per-TTI dynamic scheduling of PDDDCH.

An LTE DCI may be used for mWTRU beam scheduling. A two-stage schedulingmechanism using LTE channels and mmW PDDCCH may be applied to reduce theLTE channel use by mmW scheduling. The mmW narrow beam pattern may carrydedicated PDDCCH and PDDDCH. The dedicated PDDCCH may include dynamicper-TTI scheduling information associated with one or more PDDDCHs. Thelong-term scheduling information may be carried in an LTE DCItransmitted in PDCCH, EPDCCH, or MAC control element, which may include,for example, transmit beam scheduling, receive beam scheduling, PDDCCHconfiguration (e.g., frequency, time, and/or code (scrambling)configuration), modulation and coding scheme (e.g., may be predefinedand not included), and/or demodulation reference signal configurationfor PDDCCH. This scheduling information may be read periodically ortriggered by one or more predefined events.

FIG. 22 illustrates an example of PDCCH and PDDCCH scheduling of PDDDCH.As illustrated in FIG. 22 , an mWTRU may monitor PDCCH 2204 (in LTEsub-frame N 2202), for example, as specified in LTE standards. The mWTRUmay detect an LTE DCI carried in its PDCCH, e.g., using its C-RNTI. ThemWTRU may decode the scheduling information for transmit and receivebeam assignment 2206, dedicated PDDCCH configuration, etc. The mWTRU,e.g., mWTRU1 may decode dedicated PDDCCH 2210 configuration to locateand/or decode PDDDCH 2212 within mmW subframe n 2208.

FIG. 23 illustrates an example of EPDCCH and PDDCCH scheduling ofPDDDCH. As illustrated in FIG. 23 , an mWTRU may monitor EPDCCH 2306 (inLTE sub-frame N 2302), for example, as specified in LTE standards. ThemWTRU may detect an LTE DCI carried in its EPDCCH, e.g., using itsC-RNTI. The mWTRU may decode the scheduling information for transmit andreceive beam assignment 2308, dedicated PDDCCH configuration, etc. ThemWTRU, e.g., mWTRU1 may use the PDDCCH 2312, e.g., within mmW subframe n2310, to locate and/or decode PDDDCH 2314.

FIG. 24 illustrates an example of LTE MAC control element and dedicatedPDDCCH scheduling of PDDDCH. As illustrated in FIG. 24 , an mWTRU maymonitor PDCCH 2404 (in sub-frame N 2402), for example, as specified inLTE standards. The mWTRU may detect an LTE DCI carried in its PDCCH,e.g., using its C-RNTI. The mWTRU may decode the PDSCH schedulinginformation. The mWTRU may read the MAC control element in PDSCH 2408and may receive mmW scheduling information 2410 including transmit andreceive beam. This may involve higher layer operation and retransmissionand may have larger scheduling latency. Beam scheduling may be along-term event. Latency may not cause issues with such beam scheduling.

FIG. 25 illustrates an example of dedicated mmPDCCH and dedicated PDCCHscheduling of PDDDCH. As illustrated in FIG. 25 , an mWTRU may monitorPDCCH 2504 (in LTE sub-frame 2502), for example, as specified in LTEstandards and may detect mmPDCCH 2508 specific LTE DCI carried in itsPDCCH using its C-RNTI. The mWTRU may decode information to receive itsupcoming mmPDCCH. The mmPDCCH specific LTE DCI may include, for example,mmPDCCH symbol location, frequency resource, transport format, and/orother configuration parameters. This mmPDCCH 2508 may not be limited toone symbol location and may span multiple symbol locations. The mWTRUmay locate and decode the mmPDCCH in the schedule symbol location of thesame LTE TTI. As the mWTRU signaled by the PDCCH (e.g., the mWTRUsignaled by the PDCCH) may read the mmPDCCH. Blind decoding may not benecessary at the symbol location. The mmPDCCH may carry mDCI, which mayinclude the beam allocation, BSRS, PDDDCH resource allocation, etc. ThemWTRUs, e.g., mWTRU1 and mWTRU2 may receive scheduling informationincluding transmit and receive beam scheduling information as describedherein.

FIG. 26 illustrates an example of multiplexed mmPDCCH and dedicatedPDCCH scheduling of PDDDCH. As illustrated in FIG. 26 , an mWTRU maymonitor PDCCH 2604 (in subframe N 2602), for example, as specified inLTE standards and may blind decode the symbol location and frequencyresources to determine if its mmPDCCH is present for mmW scheduling. AnmWTRU identity, such as C-RNTI, mmW-RNTI, or IMSI may be used toidentify the mmPDCCH 2606. The mmPDCCH 2606 may be multiplexed betweenmultiple mWTRUs and may be transmitted over a frequency allocation withconfiguration signaled over RRC signaling to mWTRUs. mWTRUs may performblind decoding at the configured symbol location and frequency resourcesaccording to their signaled mmPDCCH configuration. The mWTRU maydemodulate and decode the mmPDCCH if it is detected in the blinddecoding process and may read mDCI information. The PDCCH may not beapplied in this approach, and no PDCCH capacity may be occupied by mmWscheduling.

In the approaches illustrated in FIGS. 22-26 , the mWTRU may form thereceive beam according to the scheduled receive beam information and mayalign the mmW subframe receiving timing according to the LTE subframestart timing and a predefined timing offset. The mWTRU may correlate anddetect mmW sector BSRS and may subsequently segment BSRS according tothe scheduled BSRS configuration. The mWTRU may subsequently synchronizeits timing and frequency based on the reference signals. The mWTRU maydemodulate and decode the dedicated PDDCCH according to theconfiguration received in LTE DCI or predefined parameter signaled inhigher layer signaling, such as SIB. The mWTRU may demodulate and decodea scheduled mmW TTI PDDDCH based on the dedicated PDDCCH mDCI. The mWTRUmay read the validity period for each scheduling instance and apply thevalidity period accordingly to consecutive mmW TTIs. The mWTRU mWTRU2PDDCCH may use predictive scheduling and the validity period field inmDCI to schedule mmW TTI 6, 7, and 8 with one dedicated PDDDCH.

An mWTRU may continuously or periodically read a broad-beam-commonPDDCCH to receive beam and dynamic per-TTI scheduling information fordata transmission and configuration of two-dimensional beam-specificmeasurement of beam signal strength or beam SINR metrics. FIG. 27illustrates an example mmW system 2700 with an mmW broad beam pattern.An LTE small cell 2702 may apply a horizontal omnidirectional antenna2704 in an LTE frequency band. One or more (e.g., three) mmW PAAs may beplaced to create three mmW sectors, each with a horizontal coverage of120°. Coverage may be determined by the link budget of broad-beam-commonPDDCCH with a low-gain antenna. The channel design may use aconservative coding rate and modulation. An mmW broad beam pattern maycarry PDDCCH to achieve a wide coverage of mWTRUs. Due to the largewidth of the beam and the resulting low antenna gain, the broad beam maynot carry PDDDCH.

As illustrated in FIG. 27 , an mWTRU 2706 may attach to an SCmB using anLTE CS procedure, e.g., based on the best LTE cell and may receive mmWspecific configuration in SIB regarding the broad-beam-common PDDCCHcarried in the broad beam per sector.

The configuration may include mmW sector BSRS code indices that mayidentify an mmW sector. For example, the BSRS may use a pseudorandomsequence, such as ZC sequences with good auto- and cross-correlationproperties and with good performance against timing/frequency offset. Inthe case of ZC sequences, sector sequences may be generated based on oneZC base sequence specific to this SCmB. This may be used to identify thebroad beam.

The configuration may include mmW segment BSRS code indices that mayidentify each mmW segment within one identified sector. The mmW segmentidentity may be encoded in a control field following BSRS, for example,of three bits (e.g., up to eight identities) in a common PDDCCH. Thismay be applied to identify a narrow data beam.

The configuration may include a frequency used for the sector BSRS,segment BSRS, and the broad-beam-common PDDCCH within the narrow beam.The configuration may include subframe, periodicity, transmissionpattern, and/or other configuration parameters of the sector, segmentBSRS, and the broad-beam-common PDDCCH. The configuration may include atime domain resource, e.g., symbol location, time slot or subframe ofthe BSRS, and the broad-beam-common PDDCCH transmission. Theconfiguration may include the broad-beam-common PDDCCH transportconfiguration parameters, e.g., the information payload and transportformat of the control fields carried in the channel.

PDDDCH scheduling information may be carried in a broad-beam-commonPDDCCH. The scheduling information may include, for example, transmitand receive beam scheduling, dynamic frame structure configuration,broad-beam-common PDDCCH resource allocation, PDDDCH frequency resourceallocation, code assignment, carrier indicator, modulation and codingscheme, new data indication, redundancy version, number of layers,channel state information request, beam specific measurement request,and/or mmW UCI resource allocation.

FIG. 28 illustrates an example of multiplexed broad-beam-common PDDCCHscheduling of PDDDCH. As illustrated in FIG. 28 , an mWTRU may form anmmW narrow receive beam and may correlate and detect sector BSRS in thebroad beam. The sector BSRS may be in the sector-wide beam. An mWTRU maydetect the BSRS when it is within the range. The mWTRU may synchronizein timing and frequency with the signaled or strongest BSRS that maybelong to its associated SCmB. The mWTRU may demodulate and decode thebroad-beam-common PDDCCH in a preconfigured control period 2808according to the preconfigured transport format. The reading of PDDCCHmay be continuous, periodical or triggered by events.

The mWTRU may check the CRC or the payload using a unique mWTRU identityincluding C-RNTI, mmW-RNTI, or IMSI to determine if there is an mDCIpresent for mmW transmission. The broad-beam-common PDDCCH may bemultiplexed with multiple mWTRUs′ PDDCCH. Blind decoding may be applied.The network may signal an mWTRU via RRC signaling its broad-beam-commonPDDCCH configuration. The mWTRU may receive the PDDDCH schedulinginformation including beam and per-TTI components.

The mWTRU may form the schedule receive beam at the scheduled directionand may correlate and detect the segment BSRS of the scheduled narrowtransmit beam. Guard time may be reserved between broad-beam-commonPDDCCH and the PDDDCH to allow beam forming, automatic gain control(AGC) convergence, synchronization, etc., for an mWTRU to get ready toreceive the scheduled transmit beam. When the transmit beam is detected,the mWTRU may synchronize in timing and frequency with the scheduledsegment BSRS. The mWTRU may demodulate and decode the PDDDCH 2806 withthe help of the scheduled DMRS.

The mWTRU may read the validity period for each scheduling instance andapply the validity period accordingly to consecutive mmW TTIs. As shownby way of example in FIG. 28 , mWTRUs mWTRU1 and mWTRU2 may be scheduledin mmW TTI 0 (2804 and 2806) of mmW subframe N 2802, but mWTRU mWTRU1may have a predictive scheduling that lasts for more than at least twoTTIs (e.g., three TTIs). During the data transmission, thebroad-beam-common PDCCH may send a measurement request to an mWTRU tomeasure one or more transmit beams with measurement occasionconfiguration. During the measurement occasion, the mWTRU may cycle thebeam for beam-specific measurement as disclosed herein.

The processes and instrumentalities described herein may apply in anycombination, may apply to other wireless technologies, and for otherservices. A WTRU may refer to an identity of the physical device, or tothe user's identity such as subscription related identities, e.g.,mobile station international subscriber directory number (MSISDN),session initiation protocol (SIP) uniform resource identifier (URI),etc. WTRU may refer to application-based identities, e.g., user namesthat may be used per application.

The processes described above may be implemented in a computer program,software, and/or firmware incorporated in a computer-readable medium forexecution by a computer and/or processor. Examples of computer-readablemedia include, but are not limited to, electronic signals (transmittedover wired and/or wireless connections) and/or computer-readable storagemedia. Examples of computer-readable storage media include, but are notlimited to, a read only memory (ROM), a random access memory (RAM), aregister, cache memory, semiconductor memory devices, magnetic mediasuch as, but not limited to, internal hard disks and removable disks,magneto-optical media, and/or optical media such as CD-ROM disks, and/ordigital versatile disks (DVDs). A processor in association with softwaremay be used to implement a radio frequency transceiver for use in a WTRU(e.g., an mWTRU), UE, terminal, base station, RNC, and/or any hostcomputer.

1-22. (canceled)
 23. A wireless transmit/receive unit (WTRU), the WTRUcomprising: a processor, the processor configured to: receive a firstmessage from a network node, wherein the first message indicatesdownlink control information (DCI), and wherein the DCI indicates achannel status information (CSI) request that requests a qualitymeasurement for a beam; determine scheduling information using the DCI,wherein the scheduling information comprises information identifying areference signal; receive the reference signal from the network nodeusing the scheduling information; determine the quality measurement forthe beam based on the received reference signal; and send a secondmessage to the network node in response to the CSI request, wherein thesecond message indicates the quality measurement for the beam.
 24. TheWTRU of claim 23, wherein the quality measurement is a channel qualityindicator (CQI).
 25. The WTRU of claim 23, wherein the qualitymeasurement indicates a signal-to-noise ratio associated with the beam.26. The WTRU of claim 23, wherein the DCI further comprises one or moreof a precoding matrix indicator (PMI), a rank indicator (RI), and achannel quality indicator (CQI).
 27. The WTRU of claim 23, wherein thereference signal is a beam-specific reference signal (BSRS).
 28. TheWTRU of claim 23, wherein the beam is a millimeter wavelength (mmW)beam.
 29. The WTRU of claim 23, wherein the DCI comprises a DCI format,and wherein the processor is further configured to determine that theDCI indicates the CSI request using the DCI format.
 30. The WTRU ofclaim 23, wherein the processor is further configured to send the secondmessage to the network node using a frequency allocation associated withthe beam.
 31. A method performed by a wireless transmit/receive unit(WTRU), the method comprising: receiving a first message from a networknode, wherein the first message indicates downlink control information(DCI), and wherein the DCI indicates a channel status information (CSI)request that requests a quality measurement for a beam; determining ascheduling information using the DCI, wherein the scheduling informationcomprises information identifying a reference signal; receiving thereference signal from the network node using the scheduling information;determining the quality measurement for the beam based on the receivedreference signal; and sending a second message to the network node inresponse to the CSI request, wherein the second message indicates thequality measurement for the beam.
 32. The method of claim 31, whereinthe quality measurement is a channel quality indicator (CQI).
 33. Themethod of claim 31, wherein the quality measurement indicates asignal-to-noise ratio associated with the beam.
 34. The method of claim31, wherein the DCI further comprises one or more of a precoding matrixindicator (PMI), a rank indicator (RI), and a channel quality indicator(CQI).
 35. The method of claim 31, wherein the reference signal is abeam-specific reference signal (BSRS).
 36. The method of claim 31,wherein the beam is a millimeter wavelength (mmW) beam.
 37. The methodof claim 31, wherein the DCI comprises a DCI format, and wherein themethod further comprising determining that the DCI indicates the CSIrequest using the DCI format.
 38. The method of claim 31, wherein thesecond message is sent to the network node using a frequency allocationassociated with the beam.
 39. A wireless transmit/receive unit (WTRU),the WTRU comprising: a processor, the processor configured to: receive afirst message from a network node, wherein the first message indicatesdownlink control information (DCI); determine, using a DCI formatassociated with the DCI, that the DCI indicates a channel statusinformation (CSI) request that requests a quality measurement for abeam; determine scheduling information using the DCI, wherein thescheduling information comprises information identifying a referencesignal; receiving the reference signal from the network node using thescheduling information; determine the quality measurement for the beambased on the received reference signal; and send a second message to thenetwork node in response to the CSI request, wherein the second messageindicates the quality measurement for the beam.
 40. The WTRU of claim39, wherein the quality measurement is a channel quality indicator(CQI).
 41. The WTRU of claim 39, wherein the quality measurementindicates a signal-to-noise ratio associated with the beam.
 42. The WTRUof claim 39, wherein the DCI further comprises one or more of aprecoding matrix indicator (PMI), a rank indicator (RI), and a channelquality indicator (CQI).